If you want some trees for privacy that grow fast you should go with the Hybrid Poplar tree.
The Hybrid Poplar trees grow at a rate of 8 feet in just one year so it will provide you some nice needed privacy in your yard in around a year.
Another faster way of gaining privacy is to put up a nice wooden or vinyl privacy fence and you'll have instance privacy and it also helps secure your home from burglars as well.
My home used to get broken into at least twice every year but after I put in a wooden privacy fence my home has not been broken into.
So I have privacy with my wooden privacy fence and I have my house secured too.